Known as: Northern Rockhopper Penguin
Estimated numbers left in wild: 265,000 breeding pairs, but decreasing.
Although the northern rockhopper penguin is one of the smallest of penguins, it is considered to be among the feistiest. Only separated from its sister species, the southern rockhopper, in 2006, this penguin only weighs 2.5 kilograms to 3 kilograms and has a length of approximately 52 centimetres. The northern rockhopper is also distinguished from the southern not only on the basis of DNA, but also from external features such as longer yellow ‘eyebrows’ or crests. The body of the penguin is a dark slate in colour with a white chest and abdomen. The bill is a rust colour and the feet are a dull pink.
As the northern rockhopper penguin spends so much time in the water, it must also take good care of its feathers. The penguins preen diligently, spreading a waxy substance over the feathers to maintain their waterproof quality.
Food and feeding habits: Northern rockhopper penguins eat fish, octopuses, squid, krill, and any other available marine food source they come upon. Very often, groups of these penguins will hunt together, and the birds can dive to depths of 100 meters.
Breeding and nesting: In addition to being an aggressive bird, the northern rockhopper penguin is also very gregarious and nests in huge colonies. Rockhoppers will build their nests between grass tussocks or among tumbled rocks, and enjoy nesting on fairly inaccessible islands. These little penguins will peck anything that comes within reach of their beaks while they are nesting.
Nesting begins in July and August, with the breeding areas sometimes hosting 100,000 pairs of these penguins. The first egg laid, which is referred to as the ‘A’ egg is noticeably smaller than the second egg that is laid, and if the ‘A’ egg does manage to hatch, the chick will die within a few days. Both parent birds incubate the eggs with the assistance of a featherless brood patch that transmits more heat to the egg. The ‘A’ egg is nearer to the outside world than is the ‘B’ egg, which increases its susceptibility. As soon as the chick hatches, the female takes over the chore of feeding herself and her mate while the male cares for the young penguin. After about 25 days, the chick joins a nursery area of other chicks, called a crèche, and both parents go to sea to feed. Heavy feeding after the chicks leave the nest help to prepare the adults for the yearly moult, during which the old feathers are replaced.
It has a restricted breeding range of just seven islands with a total land area of 250 square km.
Location: The northern rockhopper penguin is found in the South Atlantic and Indian Ocean and breeds on islands in the sub-Antarctic region, especially on Gough Island, Tristan da Cunha, and St. Paul and Amsterdam Islands.
Threats: Northern rockhopper penguin populations have declined seriously in the past decades, with over 1 million birds disappearing. On some islands, this represents a loss of 90% of the population.
Commercial fishing has made inroads into the food that the penguins eat, but other threats include increased predation, egg harvesting, and pollution from ecotourism. The accidental introduction of the house mouse on nesting sites has led to nest robbing by the rodents. Oil spills present another hazard.
Conservation efforts: Northern rockhopper penguin populations are currently being monitored closely and attempts to find out exactly what has caused the decline in their numbers is being sought. Keeping commercial fishing concerns from trawling near breeding colonies can also help to stabilize populations. Marine reserves will also give the protection this lovely little penguin needs.
Do you know of or are you a part of an organisation that work to conserve the Northern Rockhopper Penguin, then please contact us to have it featured on Our Endangered World.